Central Nervous System Regulatory and Control Structures

CNS: Neural Tissue - Metabolic Needs

• Oxigen

  • passes freely across blood-brain barrier

  • Brain receives 15% of blood pumped by heart

• Glucose

  • From the total body’s glucose consumption, the brain uses about half of it

  • Membrane transporters move glucose from plasma into brain interstitifal fluid

  • Progressive hypoglycemia (not enough/low glucose) - leads to confusion, unconsciousness, and death

CNS

Consist:

• brain

• spinal cord

• Receives input from sensory neurons

• Directs activity of motor neurons

Reticular Formation (RF)

Brain stem RF → is a primitive network specialized for various kinds of simple integration

• 1st neurons to be well developed in primitive vertebrates

• 1st neurons to mature during development

• RF neurons have “primitive” shape

  • Simple bipolar or multipolar

Location

• RF has cell bodies in the main regions of the brain stem

  • Medulla

  • Pons

  • Midbrain

• RF axons run long distances

→ spinal cord: sensory and motor regulation

→ forebrain: regulation of behavioral state

Transmitters

RF transmitters: Somewhat slow-acting

Transmitters inlcude -

• Serotonin (5-HT)

• NE

Some RF neurons do not appear to have well defined postsynaptic structures ~ just release transmitter into cerebral ECF (suggested as a “modulatory” function